Nit: "due to"
Start with capital letter "Fix"
On Tue, Mar 02, 2021 at 01:06:52PM +0800, Tianjia Zhang wrote:
On 3/1/21 5:54 PM, Jarkko Sakkinen wrote:
On Mon, Mar 01, 2021 at 01:18:36PM +0800, Tianjia Zhang wrote:
q2 is not always 384-byte length. Sometimes it only has 383-byte.
What does determine this?
In this case, the valid portion of q2 is reordered reversely for little endian order, and the remaining portion is filled with zero.
I'm presuming that you want to say "In this case, q2 needs to be reversed because...".
I'm lacking these details:
- Why the length of Q2 can vary?
- Why reversing the bytes is the correct measure to counter-measure this variation?
/Jarkko
When use openssl to generate a key instead of using the built-in sign_key.pem, there is a probability that will encounter this problem.
Here is a problematic key I encountered. The calculated q1 and q2 of this key are both 383 bytes, If the length is not processed, the hardware signature will fail.
Why is reversing bytes the correct way to fix the issue?
-----BEGIN RSA PRIVATE KEY----- MIIG4gIBAAKCAYEAnWxc9HyjCuLWtFVKm0xrkHimyeTEdx7LJpRzm07M/gLFxqwV bFEFL1SdK912H8S0yRKGzCTqrEa0AKaBhIzw19OgW1jIQx9+ybENnIYh4O+YGwKH ngTAw5Xfuw8iaPeLe3Pujg4h7ePI4cx6C98KM2tDHb0GeN35wM/2AxaWmuwMGosv kbNN2EN9zQVLIkaUtCJHH8UlfZ+QQVO32Mij46wO4O4783Hgr7PUmI7LCkk31vBT fzPch6LSgBy6UvtvBfJWo+t/Rk5aGm90JchY4+H1/23vwpkmKhRazBDbUeHVcX7f ytwJkmODIjbiapB6gf0AxQooIwJaqdRKddn/BB/IAkanG0m6COuvgP2Z9256U262 GvEWf+IHY2/DmoivAcc/koYHrRjNgcak8nPq9iTE4R9jPFj41+2r5k3AycCGlt75 HdYP1oZ/F0nTKp8yGOsf61DXaQLXPnPyjQunKGjBQONJb7Kj/8TOJjSuh7cdRqRP OXGZPwOEkhKU4QwtAgEDAoIBgGjy6KL9wgdB5Hg43GeIR7WlxIaYgvoUh28NomeJ 3f6sg9nIDkg2A3TjE3KTpBUtzdthrzLDRx2EeABvAQMIoI/iaueQhYIU/zEgs72u wUCfurysWmlYgIJj6ny0wZtPslJNSbQJa/PtMJaIUV0/XCJHghPTWaXpUSs1Tqy5 ubydXWcHdQvM3pAs/oiuMhbZuHgW2hUuGP5qYCuNJTswbUJytJX0J/ehQHUijbsJ 3LGGJTn1jP936FpsjFVofDdSSPgwF5a8TgxtIHNK8cuXq2gyblmo7afszujVJhib VqbYtL9UYwg/oibI+hFGxMGgDUqQlZg9E7/1QnMNRsubm7sWBO+hTA+fdwVY7+zh CtOLb7XDbHWF1+k+DDd2m4SibyBr7zsHkIO9DoDwHWvCSW+SICcfdTeCmxGPYfeZ P8QDxWj25zjS8e93/zgyMuiQY8T6AEajFU0VIZfhoHKeOYs8Vg3T30z+SwSVsTLl DDFq2PHkYg7dG14n3iFa0DXckwKBwQDOmlmLVVIVPQcDreS2sLkO/a44zzIyFwvA eItWkBWSF/1nY8Nh0dDw7Hn8QRMHoxC4pLjTxsGMLD9f5YAXZueRcjOuhnDfalpB 5M11A9QKQFB0ar/viq5Kyl6Jxv3PFdkszaRcwmxCdhjv/OL4kxfZ1gEvqeZLPLh5 fWdyNQrXBhbGrfmDQfs/d+yMmHzvJJ7rO9VXKHhqMU1QkjQFh7AjOj6PI58oEE8F eND4d+0Y5Mi4F+1jvBvshNbjcgPFjnMCgcEAww/Ztnu4Hm2iadEkvbQeuJiiQCFZ FJ7kDFwWUJfDxYTI6xyH3KrFZ0mSDAuoQH1V2X9njOfI9uY3nVrgLQmt2gyM7E5E JHAtPwF6KKg1r90CTl7Tex2kVzqWhnbchH8vJFe0XThCpQce0GGV2D1k9POTdsZN HdhXxBkxgLLWTLTHsr6kxVepr9qTtmYJ3qH9hjhKKjO/CzHXig9N25agtFQBnQHb VCTkc2tzYWUvJLIPI7XOv2nURULgfJhYyrLfAoHBAIm8O7I44WN+BK0emHnLJgn+ dCXfdswPXSr7B48KuQwP/kTtLOvhNfXy+/2At1pstdBt0I0vK7LIKj/uVWTvRQuh d8mu9epG5taYiPitOAbVivhHKp+xyYcxlFvZ/ooOkMiJGD3W8tb5ZfVTQfsMupE5 Vh/GmYd90FD+RPbOBzoEDy8epleBUipP8whlqJ9tv0d9OOTFpZwg3jW2zVkFIBd8 KbTCahq1igOl4KWlSLtDMHq6nkJ9Z/MDOez2rS5e9wKBwQCCCpEkUnq+88Gb4MMp Ir8luxbVa5C4ae1dkrmLD9fZAzCcva/ocdjvhmFdXRrVqOPmVO+zRTCkmXpo50Ae BnPmswidiYLC9XN/VlFwcCPKk1be6eJSE8Lk0bmu+ehYVMoYOng+JYHDWhSK67k6 05ijTQz52Yi+kDqCu3ZVzI7dzdp3KcMuOnEf5w0kRAaUa/5ZetwcIn9cy+UGtN6S ZGsi4qu+ATziw0L3nPeWQ3TDIV9tI98qRo2Dger9uuXcdz8CgcA1J+UJh7WX9kT4 OBIKkb1TftyT2LZyzBh2LcrueUIU3gka8IqI6X/B9lB6WTLCtuBGWZZLRAuuuWlL nEm2TuTtU0Ir7/3lnZ/Fmc5/Ams4cGfxl1oXdiXoARSLR6HdvIIBZ8GdUqISR1M1 IMMQtRIWomsRCfN0IUvgi0bTUkE5dZp8UFThZp22CahWgEq5h63pNF0K8hHdEyWb aaMCoAFhIcU4UBUDUxREyY7y1eUCWKAl0B4xEvJoxolbYyTvQB4= -----END RSA PRIVATE KEY-----
good luck!
Tianjia
/Jarkko